2 * linux/fs/nfsd/nfssvc.c
4 * Central processing for nfsd.
6 * Authors: Olaf Kirch (okir@monad.swb.de)
8 * Copyright (C) 1995, 1996, 1997 Olaf Kirch <okir@monad.swb.de>
11 #include <linux/module.h>
12 #include <linux/sched.h>
13 #include <linux/time.h>
14 #include <linux/errno.h>
15 #include <linux/nfs.h>
17 #include <linux/uio.h>
18 #include <linux/unistd.h>
19 #include <linux/slab.h>
20 #include <linux/smp.h>
21 #include <linux/freezer.h>
22 #include <linux/fs_struct.h>
23 #include <linux/kthread.h>
24 #include <linux/swap.h>
26 #include <linux/sunrpc/types.h>
27 #include <linux/sunrpc/stats.h>
28 #include <linux/sunrpc/svc.h>
29 #include <linux/sunrpc/svcsock.h>
30 #include <linux/sunrpc/cache.h>
31 #include <linux/nfsd/nfsd.h>
32 #include <linux/nfsd/stats.h>
33 #include <linux/nfsd/cache.h>
34 #include <linux/nfsd/syscall.h>
35 #include <linux/lockd/bind.h>
36 #include <linux/nfsacl.h>
37 #include <linux/seq_file.h>
40 #define NFSDDBG_FACILITY NFSDDBG_SVC
42 extern struct svc_program nfsd_program;
43 static int nfsd(void *vrqstp);
44 struct timeval nfssvc_boot;
47 * nfsd_mutex protects nfsd_serv -- both the pointer itself and the members
48 * of the svc_serv struct. In particular, ->sv_nrthreads but also to some
49 * extent ->sv_temp_socks and ->sv_permsocks. It also protects nfsdstats.th_cnt
51 * If (out side the lock) nfsd_serv is non-NULL, then it must point to a
52 * properly initialised 'struct svc_serv' with ->sv_nrthreads > 0. That number
53 * of nfsd threads must exist and each must listed in ->sp_all_threads in each
54 * entry of ->sv_pools[].
56 * Transitions of the thread count between zero and non-zero are of particular
57 * interest since the svc_serv needs to be created and initialized at that
60 * Finally, the nfsd_mutex also protects some of the global variables that are
61 * accessed when nfsd starts and that are settable via the write_* routines in
62 * nfsctl.c. In particular:
64 * user_recovery_dirname
68 DEFINE_MUTEX(nfsd_mutex);
69 struct svc_serv *nfsd_serv;
72 * nfsd_drc_lock protects nfsd_drc_max_pages and nfsd_drc_pages_used.
73 * nfsd_drc_max_pages limits the total amount of memory available for
74 * version 4.1 DRC caches.
75 * nfsd_drc_pages_used tracks the current version 4.1 DRC memory usage.
77 spinlock_t nfsd_drc_lock;
78 unsigned int nfsd_drc_max_mem;
79 unsigned int nfsd_drc_mem_used;
81 #if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
82 static struct svc_stat nfsd_acl_svcstats;
83 static struct svc_version * nfsd_acl_version[] = {
84 [2] = &nfsd_acl_version2,
85 [3] = &nfsd_acl_version3,
88 #define NFSD_ACL_MINVERS 2
89 #define NFSD_ACL_NRVERS ARRAY_SIZE(nfsd_acl_version)
90 static struct svc_version *nfsd_acl_versions[NFSD_ACL_NRVERS];
92 static struct svc_program nfsd_acl_program = {
93 .pg_prog = NFS_ACL_PROGRAM,
94 .pg_nvers = NFSD_ACL_NRVERS,
95 .pg_vers = nfsd_acl_versions,
98 .pg_stats = &nfsd_acl_svcstats,
99 .pg_authenticate = &svc_set_client,
102 static struct svc_stat nfsd_acl_svcstats = {
103 .program = &nfsd_acl_program,
105 #endif /* defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL) */
107 static struct svc_version * nfsd_version[] = {
108 [2] = &nfsd_version2,
109 #if defined(CONFIG_NFSD_V3)
110 [3] = &nfsd_version3,
112 #if defined(CONFIG_NFSD_V4)
113 [4] = &nfsd_version4,
117 #define NFSD_MINVERS 2
118 #define NFSD_NRVERS ARRAY_SIZE(nfsd_version)
119 static struct svc_version *nfsd_versions[NFSD_NRVERS];
121 struct svc_program nfsd_program = {
122 #if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
123 .pg_next = &nfsd_acl_program,
125 .pg_prog = NFS_PROGRAM, /* program number */
126 .pg_nvers = NFSD_NRVERS, /* nr of entries in nfsd_version */
127 .pg_vers = nfsd_versions, /* version table */
128 .pg_name = "nfsd", /* program name */
129 .pg_class = "nfsd", /* authentication class */
130 .pg_stats = &nfsd_svcstats, /* version table */
131 .pg_authenticate = &svc_set_client, /* export authentication */
135 u32 nfsd_supported_minorversion;
137 int nfsd_vers(int vers, enum vers_op change)
139 if (vers < NFSD_MINVERS || vers >= NFSD_NRVERS)
143 nfsd_versions[vers] = nfsd_version[vers];
144 #if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
145 if (vers < NFSD_ACL_NRVERS)
146 nfsd_acl_versions[vers] = nfsd_acl_version[vers];
150 nfsd_versions[vers] = NULL;
151 #if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
152 if (vers < NFSD_ACL_NRVERS)
153 nfsd_acl_versions[vers] = NULL;
157 return nfsd_versions[vers] != NULL;
159 return nfsd_version[vers] != NULL;
164 int nfsd_minorversion(u32 minorversion, enum vers_op change)
166 if (minorversion > NFSD_SUPPORTED_MINOR_VERSION)
170 nfsd_supported_minorversion = minorversion;
173 if (minorversion == 0)
175 nfsd_supported_minorversion = minorversion - 1;
178 return minorversion <= nfsd_supported_minorversion;
180 return minorversion <= NFSD_SUPPORTED_MINOR_VERSION;
186 * Maximum number of nfsd processes
188 #define NFSD_MAXSERVS 8192
190 int nfsd_nrthreads(void)
193 mutex_lock(&nfsd_mutex);
195 rv = nfsd_serv->sv_nrthreads;
196 mutex_unlock(&nfsd_mutex);
200 static void nfsd_last_thread(struct svc_serv *serv)
202 /* When last nfsd thread exits we need to do some clean-up */
203 struct svc_xprt *xprt;
204 list_for_each_entry(xprt, &serv->sv_permsocks, xpt_list)
207 nfsd_racache_shutdown();
208 nfs4_state_shutdown();
210 printk(KERN_WARNING "nfsd: last server has exited, flushing export "
215 void nfsd_reset_versions(void)
220 for (i = NFSD_MINVERS; i < NFSD_NRVERS; i++) {
221 if (nfsd_program.pg_vers[i])
226 for (i = NFSD_MINVERS; i < NFSD_NRVERS; i++)
227 nfsd_program.pg_vers[i] = nfsd_version[i];
228 #if defined(CONFIG_NFSD_V2_ACL) || defined(CONFIG_NFSD_V3_ACL)
229 for (i = NFSD_ACL_MINVERS; i < NFSD_ACL_NRVERS; i++)
230 nfsd_acl_program.pg_vers[i] =
237 * Each session guarantees a negotiated per slot memory cache for replies
238 * which in turn consumes memory beyond the v2/v3/v4.0 server. A dedicated
239 * NFSv4.1 server might want to use more memory for a DRC than a machine
240 * with mutiple services.
242 * Impose a hard limit on the number of pages for the DRC which varies
243 * according to the machines free pages. This is of course only a default.
245 * For now this is a #defined shift which could be under admin control
248 static void set_max_drc(void)
250 #define NFSD_DRC_SIZE_SHIFT 10
251 nfsd_drc_max_mem = (nr_free_buffer_pages()
252 >> NFSD_DRC_SIZE_SHIFT) * PAGE_SIZE;
253 nfsd_drc_mem_used = 0;
254 spin_lock_init(&nfsd_drc_lock);
255 dprintk("%s nfsd_drc_max_mem %u \n", __func__, nfsd_drc_max_mem);
258 int nfsd_create_serv(void)
262 WARN_ON(!mutex_is_locked(&nfsd_mutex));
267 if (nfsd_max_blksize == 0) {
268 /* choose a suitable default */
271 /* Aim for 1/4096 of memory per thread
272 * This gives 1MB on 4Gig machines
273 * But only uses 32K on 128M machines.
274 * Bottom out at 8K on 32M and smaller.
275 * Of course, this is only a default.
277 nfsd_max_blksize = NFSSVC_MAXBLKSIZE;
278 i.totalram <<= PAGE_SHIFT - 12;
279 while (nfsd_max_blksize > i.totalram &&
280 nfsd_max_blksize >= 8*1024*2)
281 nfsd_max_blksize /= 2;
284 nfsd_serv = svc_create_pooled(&nfsd_program, nfsd_max_blksize,
285 nfsd_last_thread, nfsd, THIS_MODULE);
286 if (nfsd_serv == NULL)
291 do_gettimeofday(&nfssvc_boot); /* record boot time */
295 static int nfsd_init_socks(int port)
298 if (!list_empty(&nfsd_serv->sv_permsocks))
301 error = svc_create_xprt(nfsd_serv, "udp", PF_INET, port,
310 error = svc_create_xprt(nfsd_serv, "tcp", PF_INET, port,
322 int nfsd_nrpools(void)
324 if (nfsd_serv == NULL)
327 return nfsd_serv->sv_nrpools;
330 int nfsd_get_nrthreads(int n, int *nthreads)
334 if (nfsd_serv != NULL) {
335 for (i = 0; i < nfsd_serv->sv_nrpools && i < n; i++)
336 nthreads[i] = nfsd_serv->sv_pools[i].sp_nrthreads;
342 int nfsd_set_nrthreads(int n, int *nthreads)
348 WARN_ON(!mutex_is_locked(&nfsd_mutex));
350 if (nfsd_serv == NULL || n <= 0)
353 if (n > nfsd_serv->sv_nrpools)
354 n = nfsd_serv->sv_nrpools;
356 /* enforce a global maximum number of threads */
358 for (i = 0; i < n; i++) {
359 if (nthreads[i] > NFSD_MAXSERVS)
360 nthreads[i] = NFSD_MAXSERVS;
363 if (tot > NFSD_MAXSERVS) {
364 /* total too large: scale down requested numbers */
365 for (i = 0; i < n && tot > 0; i++) {
366 int new = nthreads[i] * NFSD_MAXSERVS / tot;
367 tot -= (nthreads[i] - new);
370 for (i = 0; i < n && tot > 0; i++) {
377 * There must always be a thread in pool 0; the admin
378 * can't shut down NFS completely using pool_threads.
380 if (nthreads[0] == 0)
383 /* apply the new numbers */
385 for (i = 0; i < n; i++) {
386 err = svc_set_num_threads(nfsd_serv, &nfsd_serv->sv_pools[i],
391 svc_destroy(nfsd_serv);
397 nfsd_svc(unsigned short port, int nrservs)
401 mutex_lock(&nfsd_mutex);
402 dprintk("nfsd: creating service\n");
405 if (nrservs > NFSD_MAXSERVS)
406 nrservs = NFSD_MAXSERVS;
408 if (nrservs == 0 && nfsd_serv == NULL)
411 /* Readahead param cache - will no-op if it already exists */
412 error = nfsd_racache_init(2*nrservs);
415 error = nfs4_state_start();
419 nfsd_reset_versions();
421 error = nfsd_create_serv();
425 error = nfsd_init_socks(port);
429 error = svc_set_num_threads(nfsd_serv, NULL, nrservs);
431 /* We are holding a reference to nfsd_serv which
432 * we don't want to count in the return value,
435 error = nfsd_serv->sv_nrthreads - 1;
437 svc_destroy(nfsd_serv); /* Release server */
439 mutex_unlock(&nfsd_mutex);
445 * This is the NFS server kernel thread
450 struct svc_rqst *rqstp = (struct svc_rqst *) vrqstp;
451 int err, preverr = 0;
453 /* Lock module and set up kernel thread */
454 mutex_lock(&nfsd_mutex);
456 /* At this point, the thread shares current->fs
457 * with the init process. We need to create files with a
458 * umask of 0 instead of init's umask. */
459 if (unshare_fs_struct() < 0) {
460 printk("Unable to start nfsd thread: out of memory\n");
464 current->fs->umask = 0;
467 * thread is spawned with all signals set to SIG_IGN, re-enable
468 * the ones that will bring down the thread
470 allow_signal(SIGKILL);
471 allow_signal(SIGHUP);
472 allow_signal(SIGINT);
473 allow_signal(SIGQUIT);
476 mutex_unlock(&nfsd_mutex);
479 * We want less throttling in balance_dirty_pages() so that nfs to
480 * localhost doesn't cause nfsd to lock up due to all the client's
483 current->flags |= PF_LESS_THROTTLE;
487 * The main request loop
491 * Find a socket with data available and call its
494 while ((err = svc_recv(rqstp, 60*60*HZ)) == -EAGAIN)
499 if (err != preverr) {
500 printk(KERN_WARNING "%s: unexpected error "
501 "from svc_recv (%d)\n", __func__, -err);
504 schedule_timeout_uninterruptible(HZ);
509 /* Lock the export hash tables for reading. */
512 validate_process_creds();
514 validate_process_creds();
516 /* Unlock export hash tables */
520 /* Clear signals before calling svc_exit_thread() */
521 flush_signals(current);
523 mutex_lock(&nfsd_mutex);
527 /* Release the thread */
528 svc_exit_thread(rqstp);
531 mutex_unlock(&nfsd_mutex);
532 module_put_and_exit(0);
536 static __be32 map_new_errors(u32 vers, __be32 nfserr)
538 if (nfserr == nfserr_jukebox && vers == 2)
539 return nfserr_dropit;
540 if (nfserr == nfserr_wrongsec && vers < 4)
546 nfsd_dispatch(struct svc_rqst *rqstp, __be32 *statp)
548 struct svc_procedure *proc;
553 dprintk("nfsd_dispatch: vers %d proc %d\n",
554 rqstp->rq_vers, rqstp->rq_proc);
555 proc = rqstp->rq_procinfo;
557 /* Check whether we have this call in the cache. */
558 switch (nfsd_cache_lookup(rqstp, proc->pc_cachetype)) {
568 /* Decode arguments */
569 xdr = proc->pc_decode;
570 if (xdr && !xdr(rqstp, (__be32*)rqstp->rq_arg.head[0].iov_base,
572 dprintk("nfsd: failed to decode arguments!\n");
573 nfsd_cache_update(rqstp, RC_NOCACHE, NULL);
574 *statp = rpc_garbage_args;
578 /* need to grab the location to store the status, as
579 * nfsv4 does some encoding while processing
581 nfserrp = rqstp->rq_res.head[0].iov_base
582 + rqstp->rq_res.head[0].iov_len;
583 rqstp->rq_res.head[0].iov_len += sizeof(__be32);
585 /* Now call the procedure handler, and encode NFS status. */
586 nfserr = proc->pc_func(rqstp, rqstp->rq_argp, rqstp->rq_resp);
587 nfserr = map_new_errors(rqstp->rq_vers, nfserr);
588 if (nfserr == nfserr_dropit) {
589 dprintk("nfsd: Dropping request; may be revisited later\n");
590 nfsd_cache_update(rqstp, RC_NOCACHE, NULL);
594 if (rqstp->rq_proc != 0)
598 * For NFSv2, additional info is never returned in case of an error.
600 if (!(nfserr && rqstp->rq_vers == 2)) {
601 xdr = proc->pc_encode;
602 if (xdr && !xdr(rqstp, nfserrp,
604 /* Failed to encode result. Release cache entry */
605 dprintk("nfsd: failed to encode result!\n");
606 nfsd_cache_update(rqstp, RC_NOCACHE, NULL);
607 *statp = rpc_system_err;
612 /* Store reply in cache. */
613 nfsd_cache_update(rqstp, proc->pc_cachetype, statp + 1);
617 int nfsd_pool_stats_open(struct inode *inode, struct file *file)
620 mutex_lock(&nfsd_mutex);
621 if (nfsd_serv == NULL) {
622 mutex_unlock(&nfsd_mutex);
625 /* bump up the psudo refcount while traversing */
627 ret = svc_pool_stats_open(nfsd_serv, file);
628 mutex_unlock(&nfsd_mutex);
632 int nfsd_pool_stats_release(struct inode *inode, struct file *file)
634 int ret = seq_release(inode, file);
635 mutex_lock(&nfsd_mutex);
636 /* this function really, really should have been called svc_put() */
637 svc_destroy(nfsd_serv);
638 mutex_unlock(&nfsd_mutex);